Various benzimidazole compounds are known for their use as anthelmintic agents. For example, U.S. Pat. No. 3,574,845 to Actor et al and assigned to Smith Kline discloses 5(6)-benzene ring substituted benzimidazole-2-carbamate derivatives including 5(6)-methylthio-2-carboethoxyaminobenzimidazole and various 5(6)-alkyl-2-carbomethoxyaminobenzimidazoles.
U.S. Pat. Nos. 3,929,821 and 4,002,640 to Beard et al and assigned to Syntex disclose various 5(6)-benzene ring substituted benzimidazole-2-carbamate derivatives including 5(6)-alkylsulfinyl-2-carbomethoxyaminobenzimidazoles, as well as 5(6)-benzylsulfinyl-2-carbomethoxyaminobenzimidazole, 5(6)-phenylsulfinyl-2-carbomethoxyaminobenzimidazole, 5(6)-cycloalkylsulfinyl-2-carbomethoxyaminobenzimidazoles and 5(6)-cyclopropylmethylsulfinyl-2-carbomethoxyaminobenzimidazole.
The benzimidazoles mentioned above are said to be active orally.
Other benzimidazoles useful as anthelmintic agents are disclosed in U.S. Pat. Nos. 3,929,822, 3,929,823, 3,929,824, 3,935,209, 3,965,113 and 4,005,202 all to Beard et al and assigned to Syntex; U.S. Pat. Nos. 3,682,952 to Actor et al, 3,578,676 and 3,694,455 to Dunn, 3,915,986 and 3,969,526 to Gyurik, all assigned to Smith Kline; and U.S. Pat. No. 3,738,993 to Haugwitz et al assigned to Squibb.
The aforementioned patents teach that the benzimidazole compounds disclosed therein are useful orally in treating helminthiasis.
U.S. Pat. Nos. 3,954,791 to Loewe et al and 3,928,375 to Duwel et al, both assigned to Hoechst disclose 2-carbalkoxy-amino-benzimidazole-5(6)-phenyl and phenylthio ethers which are said to be active perorally and subcutaneously.
In accordance with the present invention, it is indeed surprising that 5(6)-phenylsulfinyl-2-carbomethoxyaminobenzimidazoles may be effectively administered parenterally in the treatment or prevention of helminthiasis inasmuch as most benzimidazole compounds are active only upon oral administration.